Currently, an artificial blood vessel that is most frequently used in the clinical field is an artificial blood vessel using a non-absorbable polymer such as GORE-TEX. Such the artificial blood vessel can exert physical property extremely close to that of a blood vessel, and brings an efficient to some extent in reconstitution of a short-term blood vessel. However, an artificial blood vessel using a non-absorbable polymer has a problem that an anti-coagulant or the like must be continuously administered since a foreign matter remains in a body over a long term after transplantation. In addition, there is also a problem that, when used in infants, it becomes necessary to perform operation again as infants are grown.
On the other hand, in recent years, a tissue regenerating method by so-called regeneration therapy has been tried. Regeneration therapy is a trial attempting to regenerate an autologous tissue by seeding cells constituting a tissue on a cell culturing scaffold that is to be an anchorage, and transplanting this. Regarding the regeneration therapy, many study examples have been reported on a variety of tissues including, for example, a skin (Non-Patent Document 1) and a cartilage (Non-Patent Document 2).
In order to apply such the regeneration therapy to revascularization, the present inventors developed a scaffold for culturing a cardiovascular tissue in which a reinforcing material comprising a bioabsorbable polymer as a core material is incorporated into a foamed polymer comprising a bioabsorbable polymer (Patent Document 1). In this scaffold for culturing a cardiovascular tissue, a foamed polymer functions as an anchorage which can adhere to seeded cells firmly, and the reinforcing material plays a role of providing strength for withstanding a blood flow after transplantation for a term until a blood vessel is regenerated, and also plays a role as a reinforcing material which provides strength for withstanding suturing. Since both of the foamed polymer and the reinforcing material comprise a bioabsorbable polymer, thereby, materials thereof are absorbed after regeneration of a blood vessel, and it becomes unnecessary to continuously use an anti-coagulant or the like. Furthermore, since a regenerated blood vessel is an autologous tissue, growth is also expected. Actually, the scaffold for culturing a cardiovascular tissue has been found to be remarkably useful in the clinical field. However, it goes without saying that a higher revascularization efficiency should be aimed for actual clinical application.    Patent Document 1: Japanese Kokai Publication 2001-78750(JP-A 200178750)    Non-Patent Document 1: M L. Cooper, L. F. Hansbrough, R. L. Spielvogel et al., Biomaterials, 12: 243-248, 1991    Non-Patent Document 2: C. A. Vacanti, R. langer, et al., Plast. Reconstr. Surg, 88: 753-759, 1991